Hi Neal,

Thank for you the quick response & suggestion. That is the obvious workaround I missed. :)

As for the contributing docs, I’ll put something together and submit a PR.

Thank you again!

Best,
Troy

On Jul 24, 2020, at 15:23, Neal Richardson <neal.p.richardson@gmail.com> wrote:


I can't answer the first question authoritatively, though off the top of my head, could you translate that to `0 - x` and use the binary operator? You may also consider posting this question to the dev@arrow.apache.org mailing list.

As for contributing tutorials and user guides, yes, please do. I believe the right location to add what you're talking about would be in https://github.com/apache/arrow/tree/master/docs/source/python.

Neal

On Fri, Jul 24, 2020 at 12:42 PM Troy Zimmerman <tazimmerman@me.com> wrote:
Hi,

I’ve written a small library that uses the ast module to parse a Python expression into a Gandiva expression tree. I’d like to able to do numeric negation (i.e. -x) in an expression, but I’ve I looked through the source code and haven’t found a way to achieve this. (I could also be missing an obvious workaround.)

Separately, are there any tutorials on using the Python bindings for Gandiva? If not, would the project be open to such a contribution? At the moment I’ve got scattershot notes of what I’ve learned from digging through the source, but could organize them into a brief tutorial or cookbook.

Best,
Troy